import time
import tkinter
import threading

#
root = tkinter.Tk()
root.title("倒计时自动关闭的窗口")
root['width']
root['height']
#
root.resizable(False, False)

#
richText = tkinter.Text(root, width=380)
richText.place(x=10, y=10, width=380, height=230)
richText.insert('0.0','假设阅读这些文字需要10秒钟时间')
#
lbTime = tkinter.Label(root, fg='red', anchor='w')
lbTime.place(x=10, y=250, width=150)

def autoClose():
    for i in range(10):
        time.sleep(1)
        lbTime['text'] = '距离窗口关闭还有{}秒'.format(10-i)
        #
        time.sleep(1)
    root.destroy()
#
t = threading.Thread(target=autoClose)
t.start()

root.mainloop()